Compensating direct-acting engine.



PATENTED MAR. 5, 1907.

W. 0. BROWN.

GOMPENSATING DIRECT ACTING ENGINE.

APPLICATION FILED SEPT. 7, 1904.

THE NORRIS PETERS co.. WASHINGTON, n. c

UNITED STATES PATENT OFFICE.

WILLIAM C. BROWN, OF PRESCOTT, ONTARIO, CANADA, ASSIGNOR TO HENRY R.WORTHINGTON, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented March 5, 1907.

Application filed September '7, 1904. Serial No. 223.576.

To all whom it may concern:

Be it known that I, WILLIAM C. BROWN, a citizen of the United States,residing at Prescott, Province of Ontario, Dominion of Canada, haveinvented certain new and useful Improvements in Compensating Direct-Acting Engines, fully described and represented in the followingspecification and the accompanying drawings, forming a part of the same.

This invention relates generally to that class of direct-acting engineswhich are provided with one or more compensating or auxiliary cylindersand pistons which are supplied with a suitable motor fluid and arearranged to act in opposition to the main piston or pistons during thefirst part of the stroke of the engine and in conjunction therewithduring the last part of the stroke, there by permitting the admission ofthe steam to the main cylinder or cylinders to be'cut off before thestroke is completed while main taining the proper power of the engine.Such compensating direct-acting engines are well known and differentforms are shown and described in various United States Letters Patent.In such compensating directacting engines the pump is liable to make toolong or too short a stroke under the varying conditions of use and theobject of the present invention is to provide suitable means forautomatically regulating or adjusting the compensating pressure so as tomaintain a practically constant stroke of the engine.

The invention may be applied to compensating engines employing anaccumulator between the compensating cylinders and source ofcompensating pressure or to engines in which no such accumulator isemployed; but certain specific features of the invention relate toconstructions employing such accumulators, and the invention will beillustrated and described in connection with such a construction.

-For a full understanding of the invention a detailed description of aconstruction embodying the same in its preferred form will 7 now begiven, reference being had to the accompanying drawings, forming a partof this specification, in which- Figure 1 is a diagrammatic sideelevation of a vertical pumping-engine embodying all the features of theinvention in their preferred form. Fig. 2 is a detail outside view ofthe tappet and regulating-valve, with the latter opened by the tappet.Fig. 3 is a vertical section of the parts shown in Fig. 2.

Referring to said drawings, A is the steamcylinder; B, thepump-cylinder; C, the forcemain; D, the air-chamber on the force-main;E, the engine cross-head; F, the compensating cylinders having theirpistons connected to the cross-head, and G the accumulator connected onone side of its piston H to the air-chamber D by pipe I and transmittingpressure to the compensating cylinders F from its smaller piston Kthrough pipe L.

The accumulator is shown as of a Wellknown construction substantiallythe same as shown in United States Letters Patent Nos. 455,935 and628,511 except for the persent invention, the effective pressure of thepiston H being adjusted by admitting compressed air from an air-tankthrough pipe 10 to the under side of the piston H and this pipe 10 beingconnected by pipe 11, controlled by cook 12 with the air-chamber at theupper end of the cylinder G for the supply of air to the air-tank asdesired. The usual gage and blow-off pipe 13 and safetyvalve 14 areshown. All the construction thus far described is old and may be of anyother common or suitable form.

Referring now to the features added for the embodiment of the presentinvention, the cross-head E carries a tappet 15, which is preferablymade adjustable, as shown, by screw 16 and set-nuts 17, and this tappetengages the upper end or the head of valve-rod 18, carrying valve 19,which is seated upon seat 1 in valve-chamber 20 by spring 21 when notengaged by the tappet 15. The valve-chamber 20 has below the valve-seat1 an inlet-pipe 22, connecting with pipe I, so as to admit air from theair-chamber D to the valve-chamber 20, and above the valve-seat 1 a pipe23, connecting with pipe 1 1, and thus through pipe 10 with the spacebelow the accumulatorpiston H. When the valve 19 is forced off the seat1 against the pressure of spring 21 by tappet 15 engaging the head ofvalve-rod 18, therefore air from the airchamber D passes through pipe22, the valvechamber, and pipe 23 to the lower side of piston H, andthus increases the pressure on the lower side of the piston H anddecreases the effective pressure tending to force the piston I-Idowward, so as to lessen the presl v I sure in the lower chamber of theaccumulator in which piston K moves, and consequently theaccumulator-pressure The amount of air that thus passes from theair-chamber l) to the accumulator-cylinder below piston H when the valveis opened by the tappet depends upon the length of time the valve 19 isopen, which obviously depends upon the distance the valve is moved bythe tappet or upon the length of the engine-stroke Leakage from theback-pressure system that is, the system supplying pressure on the backor lower side of piston ill and tending to lower the compensatingpressure-is provided so as to gradually reduce the back pressure in casethe tappet does not open the valve 19, this result being secured in theconstruction shown by an adjustable needle-valve 2 on pipe 23, whichpermits a small constant leakage of air and by which the amount of suchleakage may be adjusted. The safety-valve 14 is set so as to blow oil atthe desired point and prevent the back pressure rising too high in caseol. an excess admission of air through pipe 23.

The operation of the construction will be understood from a briefdescription in. connection with the drawings. The tappet 15 engages thevalve-rod l8 and. opens the valve 19 at the end of each stroke of fulllength in one direction, so as to admit air "rom airchamber 1) to theback-pressure system. The tappet 15 and the valve 2 are so adjusted.that on the normal stroke of the engine the valve 19 is opened by thetappet only for such a time as to compensate for the leakage from theback-pressure system. through valve 2, and thus maintain a uniform loadon the accumulator-cylinders F, or it the stroke be too long the valve19 will be open for a longer time and more air admitted to thebackpressure system, with the result that the pressure in theback-pressure system is increased and the compensating-cylinder loadslightly reduced, which will tend to shorten the stroke of the engineand gradually bring the engine back to normal stroke. it hen by reasonof shortened stroke the tappet fails to open the valve 1%), the pressureof air in the back-pressure system drops gradually on account of theleak through the valve 2, and as the back pressure decreases thecompensating-cylinder load increases and the stroke is graduallylengthened. By adjusting the taptpe 15 and the valve 2 apractically-constant stroke of the engine may readily be secured.

It will be understood that the invention is not limited. to theparticular arrangement or construction of engine and compensating systemshown nor to the particular devices shown for adjusting the compensatingpressure, but that the invention as defined by the claims may beembodied in constructions of widely-diflerent forms.

will at I claim is* 1. Ti e combination with a tlirect-acting engine,oil one or more compensating cylinders and pistons acting in oppositionto tilt on gine-piston during the first part of the stroke and inconjunction tncrewitn during the last part of its stroke, means forapplying motor iluid in opposition to the working pressure lor adjustingthe compensating-cylintler pressure, and means coi'itrolled by the lengt2i oi toe engine-stroke l or varying the rclai' iyc working and opposingpressures to vary the co]npensating-cylinder pressure.

2. The combination with a direct-acting engine, o'l one or morecompensating-cy'lii1- dcrs and pistons acting in opposition to toeengine-piston during the lirst part ot the stroke and in. conjmictiontherewith during t re last part ol its stroke, and means controlled bytrse length of the engine-stroke lor admittir fluid to the compensatingsystem inv opposition to toe working pressure to 'ary thecompensating-cvlindcr pressure.

3. Tie combination witn a dirccbacting engine, of one or morecompensating cylinders and. pistons acting in opposition to theengine-piston during the first part ol' tilt stroke and. in conjunctiontrerewitn durim: tre last part of its stroke, means controlled by tilelcngtn oi tiie engine-stroke l or adn1itting :lluid to the compensatingsystem at eacn stroke of the engine of normal or greater lei'lgtli, andan outlet from the system lor [to constant escape of fluid from thecompcn-- sating system.

4-. Tile combination with a direct-acting engine, of one-or morecompensating cylinders and pistons acting in opposition to l'lengine-piston during trio first part ol lixc stroke and in conjunctiontherewith during the last part of its stroke, means controlled by thelength of ti e engine-stroke l'or admitting lluid to the compensatingsystem in oppositionto the Working pr rsurc at each stroke oil theengine of normal or greater length, and an outlet from the system fortire escape ol fluid to lessen the opposition to the working pressure.

5. The combination with a direct-rudiug engine, of one or morecompensating cylin ders and pistons acting in. opposition to thee1'1gine ')iston during the first part of tinstroke and in conjunctiontoerewitn during tire last part of its stroke, an accumulzuor tnrougnwnich said. compensating cylinder derives its pressure, and meanscontrolled by the length of the engine-stroke for admitting :l'luid tosaid accunnilator in opposition to the working pressure to vary thecompei'isatingcylinder pressure.

6. Tire combination with a dircctacting engine, of one or morecompensating cylinders and pistons acting iii-opposition to theengine-piston during the 'lllSlZ part of the stroke and in conjunctiontherewith during adjustable outlet permitting a constant esthe last partof its stroke, an accumulator through which said compensating cylinderderives its pressure, a pipe for admitting fluid to said accumulator inopposition to the working pressure, an outlet permitting a constantescape of fluid from the back-pressure system, and a valve opened by themain piston on each stroke of normal or full length for admitting air tothe back-pressure system.

7. The combination with a direct-acting engine, of one or morecompensating cylinders and pistons acting in opposition to theengine-piston during the first part of the stroke and in conjunctiontherewith during the last part of its stroke, an accumulator throughwhich said compensating cylinder derives its pressure, a pipe foradmitting fluid to said accumulator in opposition to the workingpressure, an outlet permitting a constant escape of fluid from theback-pressure system, a tappet moving with the engine-piston, and avalve engaged by said tappet on each stroke of normal or full length toopen tFi e valve for the admission of air to the backpressure system.

8. The combination with a direct-acting pumping-engine and itsair-chamber, on the force-main, of one or more compensating cylindersand pistons acting in opposition to the engine-piston during the firstpart of the stroke and in conjunction therewith during the last part ofits stroke, an accumulator through which said compensating cylinderderives its pressure from the air-chamber, a pipe for admitting fluid tosaid accumulator in opposition to the working pressure, an outletpermitting a constant escape of fluid from the back-pressure system, atappet moving with the engine-piston, and a valve engaged by said tappeton each stroke of norma or full length to open the valve for theadmission of air to the back-pressure system.

9. The combination with a direct-acting engine and its compensatingcylinder or cylinders and accumulator, of pipe 23 connecting theback-pressure side of the accumulatorpiston with a source of pressurefluid, and a valve controlling said pipe and controlled by the length ofstroke of the enginepiston.

10. The combination with a direct-acting engine and its compensatingcylinder or cylinders and accumulator, of pipe 23 connecting theback-pressure side of the accumulator-piston with a source of pressurefluid, an

cape of fluid from said pipe, a valve controlling said pipe, andadjustable means moving with the engine-piston for admitting fluidthrough said pipe at each normal or longer stroke of the piston.

11. The combination with a direct-acting engine and its compensatingsystem, of a valve for admitting fluid to the compensating system tovary the compensating pressure, and means moving with the engine-pistonfor actuating said valve.

12. The combination with a direct-acting engine and its compensatingsystem, of an outlet permitting the constant escape of fluid from thecompensating system, a valve for admitting fluid to the compensatingsystem to vary the compensating pressure, and means moving with theengine-piston for opening said valve for the admission of fluid.

13. The combination with a direct-acting engine, of a compensatingpiston acting in opposition to the movement of the enginepiston duringone part of the stroke and in conjunction therewith during another partof the stroke, means for applying motor fluid in opposition to theworking pressure for adjusting the compensating-cylinder pressure, andmeans controlled by the length of the engine-stroke for transferringfluid from the working-pressure fluid to the fluid opposing the workingpressure to vary the compensating-cylinder pressure.

14. The combination with a direct-acting engine, of a compensatingcylinder having a piston acting in opposition to the movement of theengine-piston during one part of the stroke and in conjunction therewithduring another part of the stroke, means controlled by the length of theengine-stroke for transferring fluid from the working-pressure fluid toa supply of fluid working in opposition to the working pressure at eachstroke of the engine of uniform or greater length, and an outlet fromthe system for the escape of fluid to lessen the opposition to theworking pres sure.

In testimony whereof I have hereunto set my hand in thepresence of twosubscribing witnesses.

l/VILLIAM C. BROWVN.

Witnesses:

J. A. GRAVES, V. H. KENNEDY.

